Acquisitions - Schedule of Pro Forma Information (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2018	Oct. 01, 2017	Sep. 30, 2018	Oct. 01, 2017
Snell Advanced Media
Business Acquisition [Line Items]
Revenues	$ 659,003	$ 644,017	$ 1,944,628	$ 1,857,885
Net income (loss) attributable to Belden common stockholders	$ 92,769	$ (24,050)	$ 126,937	$ (19,056)
Diluted income (loss) per share attributable to Belden common stockholders (in usd per share)	$ 2.13	$ (0.57)	$ 3.08	$ (0.45)
Thinklogical Holdings LLC
Business Acquisition [Line Items]
Revenues		$ 621,745		$ 1,792,614
Net income (loss) attributable to Belden common stockholders		$ (5,128)		$ 37,097
Diluted income (loss) per share attributable to Belden common stockholders (in usd per share)		$ (0.12)		$ 0.87

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

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The pro forma diluted net income per share for a period as if the business combination or combinations had been completed at the beginning of a period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(2)-(3)
-URI http://asc.fasb.org/extlink&oid=79982066&loc=d3e1392-128463

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The pro forma net Income or Loss for the period as if the business combination or combinations had been completed at the beginning of a period.

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The pro forma revenue for a period as if the business combination or combinations had been completed at the beginning of the period.

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